Obesity is more deadly than previously thought, but a nationwide survey shows that after rising for decades, rates have not increased for the first time in 30 years.

In the latest “F as in Fat” report, released annually by Trust for America’s Health and the Robert Wood Johnson Foundation, only one state, Arkansas, showed an increase in obesity rates while other states managed to keep their rates stable compared with the previous year. All of the 20 states with the highest obesity levels are located in the South or Midwest, with the exception of Pennsylvania. And for the first time in eight years, Mississippi is no longer the state with the highest adult obesity rate — Louisiana now holds that position with 34.7% of adults weighing in with a body mass index (BMI) above 30.

Once again, Colorado tops the list at the other end — as the state with the lowest obesity rate with 20.5% of its residents considered obese.

What helps Coloradans to stay at healthy weights, and what have states like Mississippi done to improve their standings? In Colorado, new laws require school districts to provide physical activity or recess during the day to help children burn off calories. That inspired other states — Arizona, Connecticut, Illinois, Indiana, Kentucky, Louisiana, Maine, North Carolina, North Dakota, Ohio and Tennessee — to pass similar laws.

Last year’s survey started to show that many states and cities were being proactive in addressing systemic problems contributing to childhood obesity. As TIME reported last year, New York City and Philadelphia, for example, took steps to include fresh foods at corner stores and require farmers’ markets to accept food stamps in order to encourage those in lower-income areas, where fresh produce is harder to find, to eat more fruits and vegetables. These approaches required involving entire communities to contribute to promoting exercise and improving the food environment, from retailers to vendors and schools.

Since children spent most of their days in school, changes in school-lunch menus are also contributing to lower obesity rates. States and school districts that started making these changes earlier have experienced the most success in getting children to eat healthier. In 2010, schools upped the food-quality standards for school lunches, and this year, the U. S. Department of Agriculture issued an update to nutrition standards for school snacks and drinks. The new regulations limit vending-machine snacks, also known as competitive snacks, to 200 calories. Any sodas or sports drinks sold in high schools must contain 60 calories or less in a 12-oz. serving. Elementary and middle schools can sell water, 100% fruit or vegetable juice, and low-fat or fat-free milk.

Public-health officials are hopeful that such measures will start to push obesity rates downward, and they have reason to be optimistic. Earlier last month, the Centers for Disease Control and Prevention reported decreases in obesity rates among low-income preschoolers. Between 2008 and ’11, 18 U.S. states and one territory reported declines in obesity rates among preschoolers. The findings were based on data of 12 million children ages 2 to 4, who were participating in federally funded nutrition programs. Childhood obesity rates in Florida, Georgia, Missouri, New Jersey, South Dakota and the U.S. Virgin Islands dropped by at least 1%, and while they did not experience declines, 20 other states and Puerto Rico managed to keep their current obesity rates from rising. Those improvements can be attributed to greater awareness of the dangers of obesity, as well as the effectiveness of public-health campaigns to encourage healthy eating habits beginning at young ages; some experts point to breast-feeding as a potential factor as well, since mother’s milk may contribute to lower obesity rates among toddlers.

While those trends are encouraging, the report also included some sobering news too. Obesity has become so entrenched throughout the U.S. that reversing the tide may require more intensive effort. In 2000, no state had more than 25% obese residents, but in the latest report, at least 20% of residents in every state were obese and 13 states had adult obesity rates that top 30%. And while overall obesity rates appear to have stabilized, the “F as in Fat” report shows that rates of “extreme” obesity, which was defined as having a BMI of 40 or more, increased by 350%.

That may explain why another recent report revealed another disturbing pattern among the obese. Researchers at Columbia University’s Mailman School of Public Health found that obesity was to blame for 18% of deaths among black and white men and women between ages 40 and 85, which is higher than the 5% mortality that previously attributed to being heavy.

In prior studies analyzing obesity rates, researchers lumped together those with high BMIs to show trends among the general population. The Columbia study, however, focused on how the risk for obesity-related deaths differed among the sexes, age groups and racial groups. A better understanding of how excess weight affects different subpopulations of people could lead to better ways of addressing weight loss among these groups and prevent unnecessary deaths. “We expect that obesity will be responsible for an increasing share of deaths in the United States and perhaps even lead to declines in U.S. life expectancy,” study author Ryan Masters says in a statement.

So in their analysis, Masters and his colleagues studied 19 waves of the National Health Interview Survey, in which a representative sample of U.S. adults of all ages answered a variety of questions about their lifestyle, including diet and exercise habits, and compared them with mortality records from the National Death Index between 1986 and 2006. The researchers found that the risk of obesity-related deaths increased with age, which suggests that the U.S. has yet to see the worst when it comes to mortality from excessive weight gain. “It stands to reason that we won’t see the worst of the epidemic until the current generation of kids grows old,” study author Bruce Link, a professor of epidemiology and sociomedical sciences at Columbia University, says in statement.

The new “F as in Fat” report found similar trends: obesity rates among baby boomers, for example, reached 30% in 41 states, whereas the rates among seniors over the age of 65 topped 30% in only one state, Louisiana. Those with less than a high school education and making less than $25,000 were also more likely to be obese compared with those who graduated or in higher-income groups.

Fortunately, these patterns are reversible, as states that have taken steps to address access to healthy foods have learned. If more fruits and vegetables are available in schools, for example, students will eat them, and cities that establish walking and biking programs also see more of its citizens becoming physically active. While obesity rates are still high, they appear to be stalling, and it’s important to build on that momentum. “In talking about this year’s report, we considered renaming it F as in Forward because we honestly believe real and lasting progress is being made in the nation’s effort to turn back the obesity epidemic,” the report’s authors write.